The present invention is generally directed to a solid oxide fuel cell (SOFC) system configured to maintain a non-oxidizing anode environment.
Fuel cells are electrochemical devices which can convert energy stored in fuels to electrical energy with high efficiencies. A solid oxide fuel cell (SOFC) generates electrical energy and reactant product from fuel and oxidizer. The SOFC contains a ceramic electrolyte, a negative or fuel electrode and a positive or oxygen electrode. The electrolyte is usually a doped zirconia ceramic. The negative or fuel electrode (referred hereto as the “anode” electrode) may be made from a cermet, such as a nickel-yttria stabilized zirconia (“YSZ”) or nickel-scandia stabilized zirconia (SSZ) cermet. The positive or oxygen electrode (referred hereto as the “cathode” electrode) is usually made of a ceramic perovskite material, such as lanthanum strontium manganite (“LSM”) having a formula (La,Sr)MnO3 or lanthanum strontium cobaltite (“LSCo”) having a formula (La,Sr)CoO3. Furthermore, contact layers, such as a Ni or nickel oxide anode contact layer and an LSM or LSCo cathode contact layer may be formed on the anode and cathode electrodes, respectively. The SOFC is usually part of a system that includes electrically connected fuel cells and other components, such as gas separator/interconnect plates, seals, and electrical contacts. Each gas separator/interconnect plate contacts the electrode and/or current collector layer of adjacent fuel cells.